Forming flanged or beaded containers



Aug. 12, 1947. K. PALMER ET AL 2,425,390

FORMING FLANGED OR BEADED CONTAINERS Filed Jan. 15, 1946 FIG 1. m 18 12 12 1s 7 L ll I A \\l V 11 17 1(6\Z5 FIG. 2.

KENDRICK PALMER ROBERT E. KUGLER HARVEY M. BRYANS INVENTORS Patented Aug. 12, 1947 UNITED STATES PATENT OFFICE FORIWING FLAN GED OR BEADED CONTAINERS Application January 15, 1946', SerialNo. 641,394

15 Claims.

The present invention relates to containers, and more particularly to the formation of deep-drawn one-piece containers from a sheet of thermoplastic material.

The principal object of the invention is the provision of a method for forming such drawn containers with enlarged peripheral portions.

A further object of the invention is the provision of a method of drawing such containers so as to provide controlled enlarged peripheral portions at selected positions on the container.

Still another object of the invention isthe provision of a method for forming controlled enlarged peripheral portions which is simple, easy and highly effective in its results.

To these and other ends, the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the meld the specification.

In the drawings:

Figs. 1 to-4 diagrammatically show the various steps in forming a deep-drawn container from a web or sheet of thermoplastic material to provide outturned flanges or beads on the upper edge" of the container;

Fig. 5 is a fragmentary view of a container formed by the method illustrated in Figs. 1 to 4, showing one form'of marginal flange;

Fig. 6 is-a view similar toFig. 5, but showing a different form of marginal flange or bead;

Fig. 7 is a partial vertical sectional view of a container formed with the reinforcing bead'or rib and a marginal flange;

Fig. 8 is a sectional view of a portion of the drawing mechanism, showing a forming platefor forming the bead of the type illustrated in Fig. 6 and Fig. 9 is a vertical sectional View through the drawing punch and the sheet restraining plates and the associated parts.

Similar reference numerals throughout the various views indicate the same parts.

The present invention relates to-a method of forming beads, flanges, or reinforcing ribs on deep-drawn containers -made from a web or sheet of a thermo-plastic material H. The sheet has its edges l2 loosely held or restrained between an upper and a lower plate l3 and M respectively which serves to restrain but not clamp the sheet II in a plane. The plates I3'and l4 are formed with registry openings |5andl6 which leave the central portion H of the sheet II unsupported. Atforming member punch or plunger IB may be moved through the openings l5 and Hi to deform the sheet II, as shown in Figs. 2 to 4, to form or draw thecontainer from the sheet 1. As the mechanism for operating the plunger 18 forms no part of the present invention, such mechanism has not been described or illustrated.

The various steps and the method of forming the container will first be described, after which the structural details of the forming plates l3 and I4 will be set forth.

The plates 13 and [4 are first separated, as shown in Fig. 9, the sheet H which is preferably, although not necessarily, in the'form of a circular disk, is laid on the plate l4- to overlie the aperture l6 and substantially concentric therewith. The upper plate 13 is then lowered to engage the sheet H and to cooperate with the lower plate M to hold loosely or to restrain the sheet H in a plane therebetween. The plates 13 and 14 do not, however, actually clamp and rigidly hold the edges l2 against movement; but permit slipping of the edges I2 between the plates, as willbe later pointed out.

The parts arethen in the position shown in Fig. 1- with the punch 18 moved to its elevated position and with the axis of movement thereof in alignment with the axis of the apertures l5 and I6 and normal tothe plane of the sheet II. The diameter of the punch 18 is slightly less than that of the apertures 15 and IE to permit the free passing of the punch therethrough, as will be apparent. The punch is moved downwardly until it engages the sheet H. Further movement of the parts then serves to draw the sheet ll downwardly between the edges of the punch and the edges of the apertures 15' and 16 and causes the sheet to adhere and conform to the shape of the punch, as illustrated in Fig. 2. During this forming operation, the restrained edges I2 move inwardly between the plates I3 and [4' to prevent the thinning of the sheet during' the drawing operation and thus providing a container of uniform thickness.

Whenthe punch reaches the'position shown in Fig. 2, theentire drawn portion of the sheet conforms to the shape of the punch. When this point is reached, the. downward speed of the punch'is quickly increased: This sudden increase of speed prevents the final portion of the drawn sheet II from moving inwardl and conforming with the surface of the punch, thus leaving a small outwardly flared portion 20, as shown in Fig. 3. Immediately after the formation of the flare 20, a cutting member or knife 2| carriedby the punch 20, cooperates with the edges of' the apertures I5 and It to sever the upper end of the container shown in Fig. 3 may then be removed,

from the punch 48. In most cases, however, it is desirable to provide the upper annular edges 22 of the container with an outwardly turned flange upper edge 23, as shown in Figs. 4 and 5. In order to form such a flange, the punch i8 is movedupwardly after reaching the position shown in Fig. 3, as indicated by the arrows. This upward movement of th punch carries the tightly gripped con- 7 tainer therewith until the upper edge 24 oithe flare 20 engages the under flat surface 25 of the lower plate [4. Upon such engagement, further upward movement of the punch l8 causes the edge 24 to move or slide outwardly or laterally along the surface 25 until the flare 20 is bent into a flange 23 which is turned at right angles to the side 26 of the container, as illustrated in Fig. 4. Thus by moving the drawn container with its flared upper end 20 upwardly against the surface 25, the flare is bent outwardly into the flange 23, of the shape best shown in Fig.

Instead of forming a bent-out flange 23, it may be desirable to turn the flar 28 into a suitablyshaped bead 27 such, for example of the shape shown in Fig. 6. In order to form such a bead, the under side of the lower plate I4 is provided with an opening 28 adapted to receive the flare 20 when the punch is moved upwardly to bend the flare outwardly and then back on itself to form the rolled bead 21 illustrated in Fig. 6.

While only one form of bead has been shown, it is contemplated and is obvious that other shaped beads'may be formed by merel altering the shape of the opening 28. The particular shape of bead to be formed may depend'eit'her on choice'or on the particular purpose for which the'container is to .be used.

The above-described method relates to the formationof an outturned flange or bead on the upper edge of the drawn container. It is sometimes desirable, however, to form circumferential reinforcing ribs 29 on the side 26 of the container intermediate the bottom 30 and the upper edge 22, as shown in Fig. '7. 'Such reinforcing ribs may be formed by the method above described by causing a change in speed of'the forming punch at the point ,where a'rib is to be provided. To secure this result, the punch 18 is 'moved downwardly, and when the point is" reached at which it is desired to form a rib 29, the speed of the punch is quickly increased. This sudden increase in speed effectively prevents the small subsequent portion of the sheet material I I from hugging 'or conforming to the side of the punch, This portion will then extend out from the punch to a diameter slightly greater than the diameter of the balance of the container to provide the reinforcing rib 29, illustrated in Fig. 8. Of course, the upper marginal flange or bead may be formed in the manner above described by again increasing thespeed of the punch near the end of .the drawing operation to form the flare 20.

' ber of such ribs may be provided depending on the length and size of the container.

.;!3Y n ae e "th 7 above e h are smooth-walled containers may be provided with a flange or bead on the upper edg thereof. In addition, the side walls may be provided with reinforoing ribs formed during the drawing operation and while the container is still on the forming punch. In'all cases, the flange, bead, or ribs extend laterally from andare of a diameter great: er than the main body of the container, and may I be broadly designated as enlarged peripheral portions, the positions of which may be controlled by varying the speed of the punch during the forming or drawing operations.

While the flare, 2i] and the ribs 29 are formed by suddenly increasing the downward or forming speed of the punch I8, such configuration may also be produced by bringing the punch to a stop,

for example, at the position shown in Fig, 2, and then'moving the punch at a fast speed thereafter. The important thing is, however, the change in speed with or Without the actual stopping of the punch.

vAfter the container has been completed, it may be removed from the punch. I the preferred arrangement, a blast of compressed air is utilized to slidably remove or reject the container from the punch. This ejecting air is supplied through the hollow supporting rod 35 of the punch and a bored plug 36, positioned in the punch,to recess 3'! formed in the punch bottom 38. By means of this arrangement, air pressure is applied to the bottom 30 of the container, and the recess 37 serves to distribute the pressure so as to prevent local deformation of the container bottom 30 by the ejecting air blast.

The plates l3 and I4 are of the shape best shown in Fig. 9 and are suitably secured, as by screws 39, to the supporting members 40 and 4|. The latter are formed with opening-s 42 and 43 respectively arrangedin alignment and concentrio with but larger than the forming apertures l5 and I6 of the plates l3 and I4, asclearl illustrated in Fig. 9. In order to maintain the various openings and forming apertures in alignment, the supporting member 40 has secured thereto depending guide rods 44 which extend through aligned bushings 45 carried by the member 4|.

In order to successfully draw a container of the class above described, from a sheet of thermo-plastic material, the sheet must be heated to make it sufi'iciently plastic for drawing. The actual temperature to which the sheet isto be heated depends, of course, on the composition or theopening 43 thereof. The heat from the element 46, transmitted throughthe member 4|,

serves to heat the heldiedges I2 of thesheet l, as is apparent. The heat transmitted to the edges I2 is conducted through the sheet Il to heat the latterwhile it isrestrained bythe plates I3 and 14 to maintain the sheet ma plastic condition suitable for drawing. V I r r The present invention thus provides anteasy,

reliable and efficient method of forming marginal beads or flanges or peripheral reinforcing ribs on deep drawn containers made from sheetsof thermo-plastic material. While certainembodiments of the invention'have been disclosed, it is tion is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling within the scope of the appended claims.

We claim:

1. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet in a plane, conditioning the sheet for drawing, forcing a drawing member against said sheet and past th -plane thereof to cause said sheet to assume the shape of said member, and then increasing thedrawing speed of said member during the drawing operation to cause the formation on said container of an enlarged peripheral portion.

2. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet with'the central portion thereof unsupported, conditioning the sheet for drawing, forcing a drawing punch against said portion of said sheet and past the plane thereof to cause said portion to assume the shape of said member, and then increasing the drawing speed of said member during the drawing operation to cause the formation on said container of an enlarged peripheral portion. I

3. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet with the central portion thereof unsupported, conditioning the restrained sheet for drawing, forcing a drawing punch against said portion of said sheet and past the plane thereof, to cause said portion to assume the shape of said member, and then increasing the drawing speed of said member during the drawing operation to cause the formation on said container of an enlarged peripheral portion,

- 4. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, holding the edges of said sheet-to retain the latter in a plane and to provide an unsupported central portion of said sheet, conditioning the sheet for drawing while it is being held, forcing a drawing punch against said portion and past the plane of said sheet to cause the sheet material to assume the shape of said punch, and then increasing the drawing speed of said punch to form an enlarged peripheral portion while the sheet material is still on the drawing punch.

5. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, loosely holding the edges of said sheet to restrain the latter and to support the sheet in a plane with the central portion of the sheet unsupported, conditioning, said sheet for drawing by applying heat thereto, moving a forming punch against said portion and past the plane of said sheet to cause the sheet to assume the shape of said punch, stopping said punch, and then increasing the drawing speed of said punch to form an enlarged periphery on said formed container at the point of stoppage of said punch and while the container is still in said punch.

6. A method of forming a controlled peripheral enlargement on a deep-drawn container made.

from a sheet of thermoplastic material comprising, restraining the sheet in a plane, conditioning the sheet for drawing by applying heat to said sheet while it is restrained, forcing a. drawing member against said sheet and past the plane thereof to cause said sheet to assume the shape of said member, and then increasing the drawing speed of said member during the drawing operation to cause theformation on said container of an enlarged peripheral portion.

7. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet in a plane, conditioning the sheet for drawing, forcing a drawing punch against said sheet and past the plane thereof to cause the sheet to assume the shape of said member, then increasing the drawing speed of said punch during the drawing operation to cause the formation of an enlarged peripheral portion on said container while the latter is on said punch, leaving marginal portions of said sheet in said plane, and then severing the drawn container from said marginal portions.

8. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, loosely holding edge portions of said sheet to restrain the latter and to support the sheet in a plane and to provide an unsupported central portion, conditioning the restrained sheet for drawing by applying heat to said sheet while it is being held, forcing a. drawing punch against said central portion and past the plane of said sheet to cause the greater portion of said sheet to assume the shape of said punch, stopping and then quickly increasing the drawing speed of said punch to form an enlarged periphery in said container, and then severing the drawn container from said edge portions.

9. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet in a plane, conditioning the sheet for drawing, forcing a drawing membe against said sheet and past the plane thereof to cause said sheet to assume the shape of said member, and then increasing the drawing speed of said member near the end of the drawing operation to form an enlarged periphery on the upper edge of said drawn container while the latter is still on said drawing member.

10. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet by loosely hold-. ing the marginal edges thereof to support the.

sheet in a plane and to provide an unsupported central portion of said sheet, conditioning the restrained sheet for drawing, forcing a drawing punch against said unsupported portion and past the plane of said sheet to cause said sheet to assume the shape of said punch, then increasing the drawing speed of said punch near the end of the drawing operation to form an enlarged peripheral portion on said drawn container adjacent said held edges, and finally severing said enlarged peripheral portion from said edges so as to position said peripheral portion at the upper edge of the drawn container.

11. A method of forming a controlled peripheral enlargement on a deep-drawn container made from a sheet of thermoplastic material comprising, restraining the sheet by loosely holding the marginal edges thereof to support the sheet in a plane and to provide an unsupported central portion of said sheet, conditioning the restrained sheet for drawing by applying heat to said held edges, forcing a drawing punch against said unsupported portion and past. the. plane oflsaid sheet to. cause said sheet to assumelthelshapefof said punch, then increasinglthe drawing sp'eedof :and finally. severing said enlarged peripheral portionfrom said edges so as to position saidperipheral portion at the upper edge of the drawn container. .l l. V 212. A method. of forming anout-turned flare on the upper edge of -a.deep-drawn container made from a; sheet of thermoplastic material comprising," restraining said sheet by loosely holding the marginal edges thereof, conditioning the restrained sheet for. drawing, forcing a drawing punch against said sheet intermediate said held edges to cause saidsh'eet to assume the'shape of said punch, then quickly increasing thedrawing speed of said punch near the end of the drawing operation to forman' outward flare on said drawn container adjacent. said held edges, and then severing said held edges to position the flare at the'uppe'r edge of the final drawn container while the latter is on the drawing punch} 13. A method of forming an out-turned flange on the upper edge of a deep-drawn container made from a sheet of thermoplasticmaterial comprising, restraining said sheet by loosely holding the marginal edges thereof, conditioning the restrainedsheet for-drawing, forcing a drawing punch against said sheet intermediate said held edges to cause saidsheet'to assume the shape of said punch, then quicklyincreasing thedrawing speed of said punch near the edge of the drawing operation to form an outward flare on 7 said drawn container adjacent said held edges,

on the-"upper edge of a deep-drawn container made from a sheet of thermoplastic material comprising, restraining said sheet byloosely holding the marginal edgesthereof, conditioning the restrained sheet for drawing, moving a drawing punch in one direction against said sheet intermediate said edges't'o cause said sheetto assume the shape. of saidlflare, thenuquickly increasing .theldrawing speed of said punch near the end of the drawingoperation to form an out-turned flare on said drawn container adjacent said edges, severing. said .edgesiromf saidv container .to. position said' fiare;at the upper edge of said container,

and' then moving, said, punch in the' opposite direction. toabring said flare into engagement with .a'forming surface tobendsaid flare into an outaturned flange positioned on the upper edge oiisaidocontainer. n, l I 7 V 15; Amethod of forming an out-turned flange on, theupner edge of a, drawn container made mmjasheet-of thermoplastic material comprising, loosely holdingthe'marginal edges of. said sheetto restrain the latter to hold the sheet in a ;plane, withthe central portion of they sheet unsupported, heat conditioning the sheet for drawingby applying heat to said edges while the sheet is restrained, moving a drawing, punch in jone direction against said central portion and Daslysaid plane tocause this portion to assume the shape lof said punch, momentarilystopping the punch adjacent the end of the drawingaoperation, then immediately increasing the drawing speed of said, punch, in said ,one direction to form an outward flare on said drawn, container' adjacent, said edges, then severing said edges from said container so that said flare is positioned on'theupperedge of said container awhile the latter ,is on said punch, and finally moving the punch in the opposite direction to bringsaid flare into' engagement with a, forming surface to, bend said flare outwardly to form an out-turned flange on the upper .edge of said cont in r.

, KENDRICK PALMER.

I ROBERT E. KUGLER.

HARVEY M. BRYANS.

I I 'REF RENoEs'oITED ffIhe' following references are of record in the me of this; patent: V p l Hf YUNI TED S'ITA'I ES PATENTS Number-" I lflai'ne Date 7 r 2,270,185" Dulm'age Jan. 13, 1942- 1 2,270,186 Dulmage Jan. 13, 1942 

